Schistosomiasis school control — DTM&H MCQ

Correct answer: E — Periodic praziquantel treatment for at-risk school-aged children

The correct answer is E, periodic praziquantel treatment for at-risk school-aged children. In high-prevalence S. mansoni settings with limited sanitation, WHO's preventive chemotherapy strategy is the scalable, cost-effective morbidity-control tool: mass or targeted administration of praziquantel to school-aged children (and other high-risk groups) at regular intervals reduces worm burden and disease before WASH infrastructure can be built. This approach does not require individual parasitological confirmation, allowing rapid coverage across whole districts. It directly targets the group with the highest intensity of infection and the greatest morbidity risk (growth stunting, anaemia, bladder or hepatic fibrosis), making it the pragmatic bridge while transmission-interrupting WASH and snail-control measures are developed. Why the other options are wrong: C. Mass rabies vaccination of dogs: this addresses a zoonotic viral disease transmitted by dog bites and has no role in a snail-borne trematode infection such as schistosomiasis. A. Individual cyst surgery for every infected child: surgery is relevant to conditions like hydatid disease or neurocysticercosis, not to schistosome infection, which causes granulomatous fibrosis rather than cysts, and is not scalable at population level. B. Indoor residual spraying: this targets indoor-resting mosquitoes for vector-borne diseases like malaria; schistosomiasis transmission occurs via freshwater snails, so vector control here means snail control, not IRS. D. Exclusive reliance on stool microscopy confirmation: microscopy has low sensitivity for light infections and confirming every case before treatment slows and limits programme reach, defeating the purpose of a scalable morbidity-control strategy. Key point: in endemic, resource-limited settings, WHO-recommended periodic mass praziquantel treatment of school-aged children, not individual diagnosis or unrelated vector interventions, is the scalable morbidity-control measure while WASH and snail control are scaled up.

Reference: WHO, Schistosomiasis fact sheet (WHO strategy: periodic, targeted preventive chemotherapy with praziquantel for school-aged children and at-risk populations), 2023, https://www.who.int/news-room/fact-sheets/detail/schistosomiasis